The TTs are crap vs. the Long Life IME. Pulled some out 2 weeks ago that were hideous. I am looking at real life results in a mildly used vehicle vs. quoting a web site like you are. I also know, with perfect certainty, the recommended service interval of the TT is NOT 100k miles. Please go check.

808, if your "upper elctrode" has wear, you have been had. The gap is important and whatever you have been sold, has failed. This is perhaps the most critical wear measurement and if someone has sold you that there is a large margin on how much that ground electrode can wear, you need to call the boss and yank their team jersey.

For example, on iridum "TT" plugs I pulled last month, the ground electrode ("upper strap"), on all plugs, was blown out to 125% of spec (.44) after 60k miles. The car was idling badly, and had just broke the copper in a coil - because of the plug I suspect after pulling them. So saving 50 cents per plug on the TT/IX type iridium had cost $60 for a coil on a 100k+ vehicle.

I will repeat, there are cheap Iridiums, and there are long-life Iridiums. They are not the same and if you are not street racing then look at what the manufacturer says and don't go to the narrower electrode. the exception seems to be NGK laser Platinums, which really last despite neither iridium metal. They are not generally cheaper than iridium plugs, but they last! I am currently trying to figure out why the NGK Laeser Patinums are more expensive than their Iridium plugs, and last about as long as Denso Long-Life Iriidium. I have seen it, Others have, and there's no clear tech reason why other than NGK puts som serious build into that line of plugs. But that's speculation, and they aren't cheap, so it's not like there's some free ride there.

 

Ahh, I wasn't aware you were speaking from experience about the TT plugs. I can see how the narrower upper electrode can wear away and cause a huge gap in turn causing the car to run bad. There is a reason why they are cheaper, but they are also marketed to performance enthusiasts who will change their plugs often anyway.

Basically from what I understand, the Iridium Long Life has a platinum upper ground Electrode vs the standard Iridium the doesn't, this is probably what contributes to its longer service life.

The NGK iridium plugs I pulled from my dad's van that had the upper electrode "eaten away" were not long life plugs, but we did get 100k from them so I'm not complaining.

I agree though for the average joe, the longer between servicing the plugs is better. $11 bucks a plug $66 total vs $8 bucks, $48 total for 6 plugs on the standard iridium is a small difference to pay for Longer service life.

Good info Oro, always nice to hear from someone with actual experience.

 

Thanks for the replies guys.

I'll change the plugs and and keep the coils as they are.

I bought 6 NGK laser iridium plugs off amazon for $ 50 Canadian including free shipping.

Don't think local shops can beat that price, Canadian tire has each plug listed as $ 20.99 plus tax lol. Even if shops could do $ 15 still wouldn't be cheaper.

 

I am at 224k miles on a 2006. I am on 3rd set of plugs. OEM set and then two NGK sets, but I am not using the pricey iridium plugs, using the $3 G plugs. I only replace them for routine maintenance reasons (approx 75kmi per set). Old plugs always do look good. I am about to install a new set.
NGK 7092 BKR6EGP G-Power

 

Not sure how I got dropped into the ES forum.
Anyways, check out the G plugs.